JavaScriptCore/wtf/FastMalloc.h - platform/external/webkit - Git at Google

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Library General Public License for more details.
  *
  *  You should have received a copy of the GNU Library General Public License
  *  along with this library; see the file COPYING.LIB.  If not, write to
  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  *  Boston, MA 02110-1301, USA.
  *
  */

 #ifndef WTF_FastMalloc_h
 #define WTF_FastMalloc_h

 #include "Platform.h"
 #include "PossiblyNull.h"
 #include <stdlib.h>
 #include <new>

 namespace WTF {

     // These functions call CRASH() if an allocation fails.
     void* fastMalloc(size_t);
     void* fastZeroedMalloc(size_t);
     void* fastCalloc(size_t numElements, size_t elementSize);
     void* fastRealloc(void*, size_t);
     char* fastStrDup(const char*);
     size_t fastMallocSize(const void*);

     struct TryMallocReturnValue {
         TryMallocReturnValue(void* data)
             : m_data(data)
         {
         }
         TryMallocReturnValue(const TryMallocReturnValue& source)
             : m_data(source.m_data)
         {
             source.m_data = 0;
         }
         ~TryMallocReturnValue() { ASSERT(!m_data); }
         template <typename T> bool getValue(T& data) WARN_UNUSED_RETURN;
         template <typename T> operator PossiblyNull<T>()
         {
             T value;
             getValue(value);
             return PossiblyNull<T>(value);
         }
     private:
         mutable void* m_data;
     };

     template <typename T> bool TryMallocReturnValue::getValue(T& data)
     {
         union u { void* data; T target; } res;
         res.data = m_data;
         data = res.target;
         bool returnValue = !!m_data;
         m_data = 0;
         return returnValue;
     }

     TryMallocReturnValue tryFastMalloc(size_t n);
     TryMallocReturnValue tryFastZeroedMalloc(size_t n);
     TryMallocReturnValue tryFastCalloc(size_t n_elements, size_t element_size);
     TryMallocReturnValue tryFastRealloc(void* p, size_t n);

     void fastFree(void*);

 #ifndef NDEBUG
     void fastMallocForbid();
     void fastMallocAllow();
 #endif

     void releaseFastMallocFreeMemory();

     struct FastMallocStatistics {
         size_t reservedVMBytes;
         size_t committedVMBytes;
         size_t freeListBytes;
     };
     FastMallocStatistics fastMallocStatistics();

     // This defines a type which holds an unsigned integer and is the same
     // size as the minimally aligned memory allocation.
     typedef unsigned long long AllocAlignmentInteger;

     namespace Internal {
         enum AllocType {                    // Start with an unusual number instead of zero, because zero is common.
             AllocTypeMalloc = 0x375d6750,   // Encompasses fastMalloc, fastZeroedMalloc, fastCalloc, fastRealloc.
             AllocTypeClassNew,              // Encompasses class operator new from FastAllocBase.
             AllocTypeClassNewArray,         // Encompasses class operator new[] from FastAllocBase.
             AllocTypeFastNew,               // Encompasses fastNew.
             AllocTypeFastNewArray,          // Encompasses fastNewArray.
             AllocTypeNew,                   // Encompasses global operator new.
             AllocTypeNewArray               // Encompasses global operator new[].
         };
     }

 #if ENABLE(FAST_MALLOC_MATCH_VALIDATION)

     // Malloc validation is a scheme whereby a tag is attached to an
     // allocation which identifies how it was originally allocated.
     // This allows us to verify that the freeing operation matches the
     // allocation operation. If memory is allocated with operator new[]
     // but freed with free or delete, this system would detect that.
     // In the implementation here, the tag is an integer prepended to
     // the allocation memory which is assigned one of the AllocType
     // enumeration values. An alternative implementation of this
     // scheme could store the tag somewhere else or ignore it.
     // Users of FastMalloc don't need to know or care how this tagging
     // is implemented.

     namespace Internal {

         // Return the AllocType tag associated with the allocated block p.
         inline AllocType fastMallocMatchValidationType(const void* p)
         {
             const AllocAlignmentInteger* type = static_cast<const AllocAlignmentInteger*>(p) - 1;
             return static_cast<AllocType>(*type);
         }

         // Return the address of the AllocType tag associated with the allocated block p.
         inline AllocAlignmentInteger* fastMallocMatchValidationValue(void* p)
         {
             return reinterpret_cast<AllocAlignmentInteger*>(static_cast<char*>(p) - sizeof(AllocAlignmentInteger));
         }

         // Set the AllocType tag to be associaged with the allocated block p.
         inline void setFastMallocMatchValidationType(void* p, AllocType allocType)
         {
             AllocAlignmentInteger* type = static_cast<AllocAlignmentInteger*>(p) - 1;
             *type = static_cast<AllocAlignmentInteger>(allocType);
         }

         // Handle a detected alloc/free mismatch. By default this calls CRASH().
         void fastMallocMatchFailed(void* p);

     } // namespace Internal

     // This is a higher level function which is used by FastMalloc-using code.
     inline void fastMallocMatchValidateMalloc(void* p, Internal::AllocType allocType)
     {
         if (!p)
             return;

         Internal::setFastMallocMatchValidationType(p, allocType);
     }

     // This is a higher level function which is used by FastMalloc-using code.
     inline void fastMallocMatchValidateFree(void* p, Internal::AllocType allocType)
     {
         if (!p)
             return;

         if (Internal::fastMallocMatchValidationType(p) != allocType)
             Internal::fastMallocMatchFailed(p);
         Internal::setFastMallocMatchValidationType(p, Internal::AllocTypeMalloc);  // Set it to this so that fastFree thinks it's OK.
     }

 #else

     inline void fastMallocMatchValidateMalloc(void*, Internal::AllocType)
     {
     }

     inline void fastMallocMatchValidateFree(void*, Internal::AllocType)
     {
     }

 #endif

 } // namespace WTF

 using WTF::fastCalloc;
 using WTF::fastFree;
 using WTF::fastMalloc;
 using WTF::fastMallocSize;
 using WTF::fastRealloc;
 using WTF::fastStrDup;
 using WTF::fastZeroedMalloc;
 using WTF::tryFastCalloc;
 using WTF::tryFastMalloc;
 using WTF::tryFastRealloc;
 using WTF::tryFastZeroedMalloc;

 #ifndef NDEBUG
 using WTF::fastMallocForbid;
 using WTF::fastMallocAllow;
 #endif

 #if COMPILER(GCC) && OS(DARWIN)
 #define WTF_PRIVATE_INLINE __private_extern__ inline __attribute__((always_inline))
 #elif COMPILER(GCC)
 #define WTF_PRIVATE_INLINE inline __attribute__((always_inline))
 #elif COMPILER(MSVC) || COMPILER(RVCT)
 #define WTF_PRIVATE_INLINE __forceinline
 #else
 #define WTF_PRIVATE_INLINE inline
 #endif

 #if !defined(_CRTDBG_MAP_ALLOC) && !(defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC)

 // The nothrow functions here are actually not all that helpful, because fastMalloc will
 // call CRASH() rather than returning 0, and returning 0 is what nothrow is all about.
 // But since WebKit code never uses exceptions or nothrow at all, this is probably OK.
 // Long term we will adopt FastAllocBase.h everywhere, and and replace this with
 // debug-only code to make sure we don't use the system malloc via the default operator
 // new by accident.

 #if ENABLE(GLOBAL_FASTMALLOC_NEW)

 #if COMPILER(MSVC)
 #pragma warning(push)
 #pragma warning(disable: 4290) // Disable the C++ exception specification ignored warning.
 #endif
 WTF_PRIVATE_INLINE void* operator new(size_t size) throw (std::bad_alloc) { return fastMalloc(size); }
 WTF_PRIVATE_INLINE void* operator new(size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
 WTF_PRIVATE_INLINE void operator delete(void* p) throw() { fastFree(p); }
 WTF_PRIVATE_INLINE void operator delete(void* p, const std::nothrow_t&) throw() { fastFree(p); }
 WTF_PRIVATE_INLINE void* operator new[](size_t size) throw (std::bad_alloc) { return fastMalloc(size); }
 WTF_PRIVATE_INLINE void* operator new[](size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
 WTF_PRIVATE_INLINE void operator delete[](void* p) throw() { fastFree(p); }
 WTF_PRIVATE_INLINE void operator delete[](void* p, const std::nothrow_t&) throw() { fastFree(p); }
 #if COMPILER(MSVC)
 #pragma warning(pop)
 #endif

 #endif

 #endif

 #endif /* WTF_FastMalloc_h */
	/*
	* Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public License
	* along with this library; see the file COPYING.LIB. If not, write to
	* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*
	*/

	#ifndef WTF_FastMalloc_h
	#define WTF_FastMalloc_h

	#include "Platform.h"
	#include "PossiblyNull.h"
	#include <stdlib.h>
	#include <new>

	namespace WTF {

	// These functions call CRASH() if an allocation fails.
	void* fastMalloc(size_t);
	void* fastZeroedMalloc(size_t);
	void* fastCalloc(size_t numElements, size_t elementSize);
	void* fastRealloc(void*, size_t);
	char* fastStrDup(const char*);
	size_t fastMallocSize(const void*);

	struct TryMallocReturnValue {
	TryMallocReturnValue(void* data)
	: m_data(data)
	{
	}
	TryMallocReturnValue(const TryMallocReturnValue& source)
	: m_data(source.m_data)
	{
	source.m_data = 0;
	}
	~TryMallocReturnValue() { ASSERT(!m_data); }
	template <typename T> bool getValue(T& data) WARN_UNUSED_RETURN;
	template <typename T> operator PossiblyNull<T>()
	{
	T value;
	getValue(value);
	return PossiblyNull<T>(value);
	}
	private:
	mutable void* m_data;
	};

	template <typename T> bool TryMallocReturnValue::getValue(T& data)
	{
	union u { void* data; T target; } res;
	res.data = m_data;
	data = res.target;
	bool returnValue = !!m_data;
	m_data = 0;
	return returnValue;
	}

	TryMallocReturnValue tryFastMalloc(size_t n);
	TryMallocReturnValue tryFastZeroedMalloc(size_t n);
	TryMallocReturnValue tryFastCalloc(size_t n_elements, size_t element_size);
	TryMallocReturnValue tryFastRealloc(void* p, size_t n);

	void fastFree(void*);

	#ifndef NDEBUG
	void fastMallocForbid();
	void fastMallocAllow();
	#endif

	void releaseFastMallocFreeMemory();

	struct FastMallocStatistics {
	size_t reservedVMBytes;
	size_t committedVMBytes;
	size_t freeListBytes;
	};
	FastMallocStatistics fastMallocStatistics();

	// This defines a type which holds an unsigned integer and is the same
	// size as the minimally aligned memory allocation.
	typedef unsigned long long AllocAlignmentInteger;

	namespace Internal {
	enum AllocType { // Start with an unusual number instead of zero, because zero is common.
	AllocTypeMalloc = 0x375d6750, // Encompasses fastMalloc, fastZeroedMalloc, fastCalloc, fastRealloc.
	AllocTypeClassNew, // Encompasses class operator new from FastAllocBase.
	AllocTypeClassNewArray, // Encompasses class operator new[] from FastAllocBase.
	AllocTypeFastNew, // Encompasses fastNew.
	AllocTypeFastNewArray, // Encompasses fastNewArray.
	AllocTypeNew, // Encompasses global operator new.
	AllocTypeNewArray // Encompasses global operator new[].
	};
	}

	#if ENABLE(FAST_MALLOC_MATCH_VALIDATION)

	// Malloc validation is a scheme whereby a tag is attached to an
	// allocation which identifies how it was originally allocated.
	// This allows us to verify that the freeing operation matches the
	// allocation operation. If memory is allocated with operator new[]
	// but freed with free or delete, this system would detect that.
	// In the implementation here, the tag is an integer prepended to
	// the allocation memory which is assigned one of the AllocType
	// enumeration values. An alternative implementation of this
	// scheme could store the tag somewhere else or ignore it.
	// Users of FastMalloc don't need to know or care how this tagging
	// is implemented.

	namespace Internal {

	// Return the AllocType tag associated with the allocated block p.
	inline AllocType fastMallocMatchValidationType(const void* p)
	{
	const AllocAlignmentInteger* type = static_cast<const AllocAlignmentInteger*>(p) - 1;
	return static_cast<AllocType>(*type);
	}

	// Return the address of the AllocType tag associated with the allocated block p.
	inline AllocAlignmentInteger* fastMallocMatchValidationValue(void* p)
	{
	return reinterpret_cast<AllocAlignmentInteger>(static_cast<char>(p) - sizeof(AllocAlignmentInteger));
	}

	// Set the AllocType tag to be associaged with the allocated block p.
	inline void setFastMallocMatchValidationType(void* p, AllocType allocType)
	{
	AllocAlignmentInteger* type = static_cast<AllocAlignmentInteger*>(p) - 1;
	*type = static_cast<AllocAlignmentInteger>(allocType);
	}

	// Handle a detected alloc/free mismatch. By default this calls CRASH().
	void fastMallocMatchFailed(void* p);

	} // namespace Internal

	// This is a higher level function which is used by FastMalloc-using code.
	inline void fastMallocMatchValidateMalloc(void* p, Internal::AllocType allocType)
	{
	if (!p)
	return;

	Internal::setFastMallocMatchValidationType(p, allocType);
	}

	// This is a higher level function which is used by FastMalloc-using code.
	inline void fastMallocMatchValidateFree(void* p, Internal::AllocType allocType)
	{
	if (!p)
	return;

	if (Internal::fastMallocMatchValidationType(p) != allocType)
	Internal::fastMallocMatchFailed(p);
	Internal::setFastMallocMatchValidationType(p, Internal::AllocTypeMalloc); // Set it to this so that fastFree thinks it's OK.
	}

	#else

	inline void fastMallocMatchValidateMalloc(void*, Internal::AllocType)
	{
	}

	inline void fastMallocMatchValidateFree(void*, Internal::AllocType)
	{
	}

	#endif

	} // namespace WTF

	using WTF::fastCalloc;
	using WTF::fastFree;
	using WTF::fastMalloc;
	using WTF::fastMallocSize;
	using WTF::fastRealloc;
	using WTF::fastStrDup;
	using WTF::fastZeroedMalloc;
	using WTF::tryFastCalloc;
	using WTF::tryFastMalloc;
	using WTF::tryFastRealloc;
	using WTF::tryFastZeroedMalloc;

	#ifndef NDEBUG
	using WTF::fastMallocForbid;
	using WTF::fastMallocAllow;
	#endif

	#if COMPILER(GCC) && OS(DARWIN)
	#define WTF_PRIVATE_INLINE __private_extern__ inline __attribute__((always_inline))
	#elif COMPILER(GCC)
	#define WTF_PRIVATE_INLINE inline __attribute__((always_inline))
	#elif COMPILER(MSVC) \|\| COMPILER(RVCT)
	#define WTF_PRIVATE_INLINE __forceinline
	#else
	#define WTF_PRIVATE_INLINE inline
	#endif

	#if !defined(_CRTDBG_MAP_ALLOC) && !(defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC)

	// The nothrow functions here are actually not all that helpful, because fastMalloc will
	// call CRASH() rather than returning 0, and returning 0 is what nothrow is all about.
	// But since WebKit code never uses exceptions or nothrow at all, this is probably OK.
	// Long term we will adopt FastAllocBase.h everywhere, and and replace this with
	// debug-only code to make sure we don't use the system malloc via the default operator
	// new by accident.

	#if ENABLE(GLOBAL_FASTMALLOC_NEW)

	#if COMPILER(MSVC)
	#pragma warning(push)
	#pragma warning(disable: 4290) // Disable the C++ exception specification ignored warning.
	#endif
	WTF_PRIVATE_INLINE void* operator new(size_t size) throw (std::bad_alloc) { return fastMalloc(size); }
	WTF_PRIVATE_INLINE void* operator new(size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
	WTF_PRIVATE_INLINE void operator delete(void* p) throw() { fastFree(p); }
	WTF_PRIVATE_INLINE void operator delete(void* p, const std::nothrow_t&) throw() { fastFree(p); }
	WTF_PRIVATE_INLINE void* operator new[](size_t size) throw (std::bad_alloc) { return fastMalloc(size); }
	WTF_PRIVATE_INLINE void* operator new[](size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
	WTF_PRIVATE_INLINE void operator delete[](void* p) throw() { fastFree(p); }
	WTF_PRIVATE_INLINE void operator delete[](void* p, const std::nothrow_t&) throw() { fastFree(p); }
	#if COMPILER(MSVC)
	#pragma warning(pop)
	#endif

	#endif

	#endif

	#endif /* WTF_FastMalloc_h */